/*
 * Copyright 2013 Robert Peszek.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *     http://www.apache.org/licenses/LICENSE-2.0
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

	package fpig.lists.structures

import fpig.lists.functions.InAndOutOfF

/**
* Base class allowing different implementations of functional lists
*
* http://code.google.com/p/fpiglet/
* @author Robert Peszek
*/
abstract class FunList<T> {
    private static final FunList _EMPTYLIST = new LazyList() //TODO where should that be defined?
    static FunList getEMPTYLIST(Map props = null) {
        _EMPTYLIST
    }
    static FunList fromOoList(List fromL, Map props = null) {
        InAndOutOfF.funlistIn(fromL, props)
    }
    static FunList funStreamFrom(n) {
        LazyList.lazyStreamFrom(n)
    }

    abstract boolean isEmpty()
    abstract T getHead()
    abstract FunList<T> getTail()
    abstract FunList<T> build(T val, Closure tailEval)
}
